Performance evaluation of grid-forming converters with AC voltage control and reactive power control

With the fast growth of renewable energy in electricity generation, grid following control, as the most widely used converter control method, experiences stability issues. Grid forming control has since been considered an increasingly attractive alternative, extensively studied, and deployed in modern distribution networks. In this paper, we compare the combinations of droop control and two control modes, AC voltage control and reactive power control, respectively. To this end, we develop a stylised model of a droop controlled converter in Simulink and conduct simulations where the converter operates in these two control modes, respectively. In these simulations, faults are also taken into account, including large-signal and small-signal disturbance, and we analyse transient and steady state performance of the droop controlled converter in each control mode. We provide insights into converter operation efficacy of the two control modes in combination with droop control and empirical guidelines on parameter tuning.